I.M. Soloveichik wrote: > There is not enough information
How do you prove it? ;)
> unless that angle at D which looks like it is > 90 is supposed to be 90--in that case the angle x is 40 degrees.
You shouldn't see what "looks like" if you cant say it for sure. The picture is only indicative. Drawing it with the right angles could be an help but it's a non-necessary condition to solve a problem.